The present invention relates generally to powered tool drivers such as electric or pneumatic power drivers. More particularly, the present invention relates to such drivers having a chuck of the keyless type.
Power tool drivers are well known. Although twist drills are the most common tools on such drivers, the tools may also comprise screw drivers, nut drivers, burrs, mounted grinding stones, and other cutting or abrading tools. Since the tool shank may be of varying diameter or of polygonal cross section, the device is usually provided with a chuck that is adjustable over a relatively wide range. The chuck may be attached to the driver by a threaded or tapered bore at any other suitable means.
A variety of chuck types have been developed that are actuated by relative rotation between a chuck body and an annular nut. In a typical oblique jawed chuck, for example, a body member includes three passageways disposed approximately 120xc2x0 apart from each other. The passageways are configured so that their center lines meet at a point along the chuck axis forward of the chuck body. Three jaws are constrained by and movable in the passageways to grip a cylindrical tool shank disposed approximately along the chuck""s center axis. The nut rotates about the chuck""s center and engages threads on the jaws so that rotation of the nut moves the jaws in either direction in the passageways. The body and nut are configured so that rotation of the nut in one direction (the closing direction) with respect to the body forces the jaws into gripping relationship with the tool shank, while rotation in the opposite direction (the opening direction) releases the gripping relationship. Such a chuck may be keyless if it is rotated by hand. Examples of such chucks are disclosed in U.S. Pat. Nos. 5,125,673 and 5,193,824, commonly assigned to the present assignee and the entire disclosure of each of which is incorporated by reference herein. Various configurations of keyless chucks are known in the art and are desirable for a variety of applications.
Keyless chucks actuated by relative rotation between a nut and a chuck body include means to control the rotational position of the nut and the body. For example, a first sleeve may be provided in communication with the nut while a second sleeve, which is independent of the first sleeve, may be attached to the body. Thus, a user may rotate the first sleeve with one hand while gripping the second sleeve with the other hand, thereby holding the body still. Alternatively, in some devices in which only a single sleeve is provided, a user may grip the single sleeve and actuate the tool driver to rotate the spindle, thereby rotating the chuck body with respect to the sleeve. In addition, a mechanism may be located in a driver to lock the spindle of the driver when the driver is not actuated, thus enabling use of a single sleeve chuck.
The present invention recognizes and addresses problems concerning drivers with hand operated chucks. Thus, broadly speaking, a principal object of this invention is an improved driver and keyless chuck arrangement.
Additional objects and advantages of the invention are set forth or will be apparent to those of ordinary skill in the art from the detailed description herein. Also, it should be further appreciated that modifications and variations to the specifically illustrated and discussed features may be practiced in various embodiments and uses of this invention without departing from the spirit and scope thereof, by virtue of present reference thereto. Such variations may include, but are not limited to, substitution of equivalent means and features for those shown or discussed, and the functional or positional reversal of various parts, or the like.
These and other objects may be achieved by a driver having a housing, rotatable drive shaft and a chuck. The chuck has a generally cylindrical body member with a nose section having an axial bore formed therein. The body has a plurality of angularly disposed passageways formed therein so that each of a plurality of jaws may be slidably positioned respectively therein. Each of the jaws has a face and threads formed thereon. A nut is in operative communication with the drive shaft and the threads on the jaws so that the drive shaft rotationally drives the nut with respect to the body to move the jaws axially within the passageways. A locking mechanism mounted to at least one of the housing and the body has two operative positions. The first rotationally locks the body and the housing with respect to one another. The second permits relative rotation between the body member and the housing.
In one preferred embodiment of the present invention, a chuck for use with a driver having a housing and a rotatable drive shaft includes a generally cylindrical body member having a nose section with an axial bore formed therein. The body has a plurality of angularly disposed passageways formed therein so that each of a plurality of jaws may be slidably positioned respectively therein. Each of the jaws has a face and threads formed thereon. A nut is in operative communication with the drive shaft and the threads on the jaws so that the drive shaft rotationally drives the nut so that the rotation of the nut with respect to the body moves the jaws axially within the passageways. A locking mechanism mounted to at least one of the housing and the body has two operative positions. The first rotationally locks the body and the housing with respect to one another. The second permits relative rotation between the body member and the housing.
Those of ordinary skill in the art will better appreciate the features and aspects of such embodiments, and others, upon review of the specification.